A top central defender is like gold dust in the modern footballing climate. It's a role that not only requires exceptional mental and physical attributes, but the ability to lead and organise a defensive line.
There are so few who have mastered the role over the years; even fewer who are still playing. Picking the top 25, then, was quite the undertaking at 90min.
After plenty of debate, however, we've managed to come up with the definitive list. Don't disagree, there's been enough of that already.
25. Caglar Soyuncu
The Turkish defender struggled to live up to the hype after his £19m move from Freiburg to Leicester in his first season at the club. He took his time to find his feet, but under Brendan Rodgers he has gone from strength to strength, playing 90 minutes in all but one game in an outstanding season for the Foxes.
He is now one of the Premier League's best, and he's only 23.
24. Ruben Dias
There is no doubt Dias, though just 22, could have had a move to one of Europe's footballing superpowers by now. He's played well over 100 games for Benfica despite his age and is already a regular for Portugal, but he has kept his feet firmly on the ground (except when he's rising to power one in from a corner) and is reaping the benefits.
He's won one Primeira Liga in Lisbon and may claim another this season, with his stock at an all-time, and rising, high.
He wasn't even close to being Atletico's biggest signing in a summer that brought them Joao Felix and Mario Hermoso among eight additions, but Felipe might have proved to be the most inspired of the lot.
Replacing Diego Godin as the experienced head at the heart of defence was never going to be easy, but since establishing himself in October he has played virtually every minute as part of La Liga's second best defence.
22. Antonio Rudiger
Since returning from injury, Rudiger has been a vital part of Frank Lampard's Chelsea side. The defensive line around him has been leaky with only Tottenham and Burnley in the Premier League's top half conceding more goals, but his performances have nonetheless been mightily impressive, and Blues fans might despair to think where they'd be without him.
21. Jerome Boateng
It wasn't too long ago that Boateng was deemed dispensable by Bayern Munich but it's difficult to imagine that now. Some fitness and suspension issues have kept him to a modest 24 appearances in all competitions, but when available he is one of the first names on Hansi Flick's team sheet.
At this rate, it would be a major surprise if he wasn't taken to Euro 2020, and that's testament to the renaissance he has enjoyed in Munich.
20. Stefan de Vrij
The market for Dutch centre-backs is a niche one, but it's not short of talent - as evidenced by the fact the imperious De Vrij is only the third highest of his countrymen on this list.
He's been exemplary for Antonio Conte's revived Inter side, and though a maiden Serie A title is fast running away from him, the ex-Lazio man remains one of the very best in the division - and indeed Europe.
19. Inigo Martinez
Athletic Club have struggled in La Liga this season, but that's not due to their defensive record. They sit in tenth place at present, but have conceded just 23 goals, bettered only by the two Madrid sides.
At the beating heart of that formidable back-line is the intelligent Martinez, who isn't the most domineering central defender you'll find in Spain, but certainly one of the most effective.
18. Mats Hummels
Hummels has been named on lists such as these for as long as any of us can remember and he will continue to be for the foreseeable. From Bayern to Dortmund, back to Bayern and then to Dortmund once again, it doesn't matter whether he's donning red and white or yellow and black, he's one of the best around, and showing no signs of slowing down as he enters his 30s.
17. Dayot Upamecano
Few centre-backs are ever able to cause the clamour and fuss over the course of their careers than Upamecano has managed in less than three seasons in the Bundesliga.
He doesn't celebrate his 22nd birthday until October but can already take his pick of the continent's biggest clubs, though will be in no hurry to leave Germany at present with domestic, and indeed Champions League, glory firmly in their sights.
16. Lucas Hernandez
A key part of France's 2018 World Cup triumph, Hernandez has struggled to hit the ground running at Bayern due to injury, but when he has featured he has shown us all what he can do - whether that be at left-back or at the heart of defence. He is one of the most highly-rated defenders around, and once he puts his fitness issues behind him for good, there is no limit to how far he can go in the game.
Having just turned 24, he has time on his side.
15. Joe Gomez
Liverpool's record with and without Gomez this season is rather astonishing. They've conceded four goals in the 14 league games he has started, and 16 in the 15 in which he hasn't.
His pace and youthful energy is vital at the heart of the back line is undeniably integral to their success, and neither Dejan Lovren nor Joel Matip can hold a candle to him now.
Ball-playing central defenders often come with the David Luiz-patented caveat of being prone to the occasional (or not so occasional in Luiz's case) howler at the back, but PSG's Marquinhos manages to strike the balance beautifully.
Graceful on the ball with an incisive eye for a pass but not lacking in any of the requisite defensive instincts, he truly can do it all.
13. Leonardo Bonucci
Bonucci is still somehow only 32 despite having played in the Italian top-flight ever since its formation in 1898, and is yet to show any signs of losing a step.
Astonishingly, he has only ever missed 12 games through injury despite having played almost 650 times for club and country. The man is essentially a cyborg programmed to do one thing: defend really, really well.
12. Thiago Silva
Another one who seems immortal, Silva is still going strong at the ripe old age of 35 as PSG trot stylishly towards another Ligue 1 title. The Brazilian captain is one of the most feared defenders in the world, and though injuries are beginning to catch up with him to a degree, he is still at the very top of his game when he takes to the pitch.
11. Niklas Sule
Injuries have ravaged Sule's 2019/20 season, but it is testament to the impression he has made that he last featured in October but is still widely regarded as one of the absolute best around.
He'll bring a big lift to Bayern Munich when he returns later this month, while Germany will also be eagerly anticipating him getting back up to speed ahead of Euro 2020.
10. Kalidou Koulibaly
The man many considered to be the creme de la creme of central defenders has gone off the boil a little along with Napoli this season but he remains a highly-coveted talent, and one of the prized assets at the Naples club.
There are few more dominant or commanding than the Senegal international, who has suffered with injuries himself, but won't be short of offers if and when he decides his time at Napoli is up.
9. Matthijs de Ligt
His transfer saga was the talk of the summer, but while his fledgling Juventus career hasn't always been plain sailing so far, by and large he has kept the faith of Maurizio Sarri, and the former Ajax defender remains a freakish talent for being so young.
At just 20, he has all the maturity and positional intelligence of a player at his peak, while his physical attributes are second to very few despite the fact he has plenty of room for development.
8. Harry Maguire
Manchester United were decisive in their approach for the former Leicester captain in the summer, but while there remains a feeling that they did perhaps overpay to secure his services, they will certainly not be regretting the decision.
He's been a block of granite at the back throughout the season so far, and will serve as the steady foundation on which they build in the years to come.
7. Milan Skriniar
Another beneficiary of the Conte revolution at Inter, Skriniar was already established as one of the world's leading defenders before the Italian arrived, but he has really hit new heights this season.
He has looked at home on the left of the back three, forging a formidable relationship with the aforementioned Godin and De Vrij, and is another who will only develop further as he approaches his peak.
6. Aymeric Laporte
It speaks to Aymeric Laporte's influence that City's grip on the Premier League title has loosened dramatically while a dodgy knee kept him on the sidelines. He once had grounds to consider himself the best around, and while others have since narrowly ousted him from the top five, few can deny his credentials as one of the very best.
5. Giorgio Chiellini
The Juventus stalwart is one of the all-time greats, and it says everything you need to know that an injury-hit 35-year-old with just a handful of appearances this season under his belt can be included this high up without a single eyebrow being raised.
A bona fide Italian football legend, and he isn't finished yet
4. Gerard Pique
Almost as irreplaceable for Barcelona as Lionel Messi? It's an argument that seems peculiar on the face of it, but when you get into the meat of it, it's hard to argue.
Pique has been an irresistible force and an immovable object all rolled into one over the years for Barca, and he has been a vital steadying influence in a wildly unstable season for the Catalan giants. Over 500 appearances and counting, he's going to take some replacing when he eventually decides to call it quits.
3. Raphael Varane
With Real Madrid boasting as many recognisable stars as they do, it's hard to give them all the plaudits they deserve, but Varane is one they certainly could not get by without.
In addition to his near-unparalleled defensive abilities, the Frenchman is a serial winner, having won everything there is to win in Madrid while also getting his hands on the World Cup in 2018. He's yet to win the Euros, of course, but you'd be daft to bet against that changing this summer.
2. Sergio Ramos
Speaking of guys who have won everything, here he is. He's probably made more enemies than he has friends with his uncompromising, rough-and-ready style, and in years to come, when the term 'shithouse' is added to the dictionary, the entry will be accompanied by a picture of Sergio Ramos' cheesing grin.
Whatever you think about Captain España, however, there is no denying that he is effective - both as an extraordinary leader and a bullet-proof defender. Few will ever match the list of honours he has racked up while in the Spanish capital, while the consistency levels he has managed over the course of his prolonged career are perhaps matched only by Lionel Messi and Cristiano Ronaldo.
1. Virgil van Dijk
However, there is only really one contender for top spot. It was expected that Van Dijk would have some job on his hands to live up to his eye-watering £75m fee when he moved to Liverpool in January 2018, but a little over two years on and that once-unthinkable price tag is looking like a drop in the bucket.
The sudden, meteoric improvement he made to the Reds upon his arrival was astounding, and it was no flash in the pan either. He has continued to amaze ever since, and though there has been the odd low point (he likely won't want to go back to Vicarage Road in a hurry) those have been absolutely and unequivocally drowned out by the vertigo-inducing highs.
He's as responsible as anyone for their famous Champions League success in Madrid in 2019, and has had no small role to play in a 2019/20 campaign that will see them add the Premier League title to the UEFA Super Cup and the Club World Cup.
He's the undisputed top dog, and it's going to take some effort to move him.